As stated, you will get between 1 1/2"-2" of lift, depending on how old those are. As much as I'd like to tell you go ahead and install, I'm going to tell you not to. Those will ride soooo bad.
I currently have the yy/by with those same struts and the ride is pretty harsh. I can imagine how harsh springs for a double cab would be. I know [MENTION=56756]1985taylor1925[/MENTION]installed those, and from what I remember, he wasn't too happy with them...I could be wrong though.
My advice is do it right the first time, even if it means it may take a bit linger to acquire the correct parts. You may try using Billy 5100s and seeing if the ride is ok, but if it sucks you'll be forced to take everything out and start all over with better springs.